• 제목/요약/키워드: sustained release

검색결과 354건 처리시간 0.022초

천식치료의 최신지견 (Update in asthma management)

  • 이혜란
    • Clinical and Experimental Pediatrics
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    • 제49권6호
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    • pp.581-588
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    • 2006
  • Asthma is a chronic inflammation of the airway associated with increased bronchial hyperresponsiveness that leads to recurrent episodes of cough, wheezing, breathless, chest tightness. According the recent studies, repeated airway inflammation leads to structural changes so called 'airway remodeling' and associated with decreased pulmonary function. Airway remodeling begins form the early stage of asthma and the early diagnosis and management is very important to prevent airway remodeling. Medication for asthma can be classified into acute symptom reliever and chronic controller. Short acting beta2 agonist is a well-known reliever that reduced asthma symptoms within minutes. Controllers should be taken daily as a long-term basis to control airway inflammation. Inhaled corticosteroid(ICS) is the most effective controller in current use. However, in some patients ICS monotherapy is not sufficient to control asthma. In those cases, other medications such as long acting beta2 agonist, leukotriene modifier or sustained-release theophylline should be added to ICS, which called Add-on-Therapy. Combination inhaler devices are easy to use. Oral leukotriene modifier has a good compliance especially in children. Finally, as asthma is a chronic disease, the development of on-going partnership among health care professionals, the patients, and the patients' family is necessary for the effective management of asthma.

Skin Permeation Enhancement of Drugs by Lipophilic and Hydrophilic Vehicles

  • Lee, Cheon-Koo;Goto, Shigeru
    • Journal of Pharmaceutical Investigation
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    • 제25권3호spc1호
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    • pp.43-51
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    • 1995
  • The in vitro skin permeability of 16 drugs with a wide span of lipophilicity (log P ranging from -0,95 to 4.40) was evaluated with an ethanol/panasate 800 (tricaprylin, P-800) (40/60) lipophilic binary vehicle and an ethanol/water (60/40) hydrophilic binary vehicle with lauric acid, The skin permeability of the drugs was enhanced by the use of the ethanol/P-800 (40/60) binary vehicle or the ethanol/water (60/40) binary vehicle with lauric acid; permeation rate was increased and lag time' was decreased. The relationship between lipophilicity and skin permeation rate of the drugs showed parabolic shapes with their peaks at much greater hydrophilic range compared with other past references. In the in vivo skin absorption of theophylline using abdominal rat skin, the ethanol/P-800 (40/60)-7% (w/w) ethycellulose gel produced a good feature as a sustained-release preparation, and the ethanol/water (60/40)-3 % (w/w) HPMC gel with lauric acid showed the highest BA value. The results suggest that the lipophilicity of a drug is a main factor for prediction of the skin permeability of the drug and that the ethanol/P-800 (40/60) binary vehicle and ethanol/water (60/40) binary vehicle with lauric acid would be good candidates for clinical transdermal application of hydrophilic drugs.

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초음파를 이용한 경피약물수송의 촉진 (Enhancement of Transdermal Drug Delivery Using Ultrasound)

  • 박승규;김태열
    • The Journal of Korean Physical Therapy
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    • 제13권3호
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    • pp.719-726
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    • 2001
  • Transdermal drug delivery offers various advantages over conventional drug delivery systems, such as avoidance gastrointestinal degradation and hepatic first-pass effect. encourages patient compliance. and possible sustained release of drugs. However, transdermal transport of drugs is low permeability of the stratum corneum, the superficial layer of the skin. Many physicochemical and biological factors influencing transdermal transport is described together with the corresponding experimental and clinical results. Phonophoresis is medical treatment with drugs introduced into the skin by ultrasound energy. Enhanced drug penetration is through to result from the biophysical alterations of skin structure by ultrasound waves. The frequency used for phonophoresis is usually from 20 kHz to 15MHz. Phonophoresis can be categorized in to three ranges: low-frequency range(below 1 MHz). therapeutic frequency range(1 to 3MHz), and high-frequency range(above 3 MHz). The depth of penetration of ultrasound into skin is inversely proportional to the frequency. Cavitation may cause mechanical stress. temperature elevation, or enhanced chemical reactivity causing drug transport. One theory is that ultrasound affects the permeation of the stratum corneum lipid structure as the limiting step in permeating through the skin. The range of indications for phonophoresis is wide. Aspecific classification of the range of indications is obtained by classification of pathological conditions. The continuous research is needed for many interesting issucs of phonophoretic transdermal delivory in new future.

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γ BST 의 유우에 대한 안정성 연구 I. γ BST가 우유중 미량광물질 조성에 미치는 영향 (Studies on the safety of recombinant bovine somatotropin in dairy cow I. Effects of recombinant bovine somatotropin on mineral composition in milk of dairy cows)

  • 이문한;조태행
    • 대한수의학회지
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    • 제31권4호
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    • pp.425-431
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    • 1991
  • Effects of recombinant bovine somatotropin$({\gamma}BST)$ on mineral composition of milk were investigated in Twenty-five multiparous Holstein dairy cows. Recombinant BST was administered by two different routes; intramusculary(12.5mg and 25mg/day) and subcutaneously (500mg and 750mg) in sustained-release vehicle every 2 weeks beginning 4 week postpartum and continuing for 7 months. Milks were collected 0,1,2,3,5 and 7 months after beginning of treatments in control and ${\gamma}BST$-administered groups. Mineral composition, such as Ca, Pi, Na, K, Mg, Zn, Fe and Mn, in milk were not affected by the administration of ${\gamma}BST$ regardless of dose and dosage forms. It is concluded from the observations of these experiments that the dose and dosage forms of ${\gamma}BST$ employed in this work might not affect milk mineral composition in dairy cows under the normal sanitary condition and adequate nutrient balance.

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랫드와 마우스에서 소성장 호르몬-서방형 제형(BST-SR)의 급성독성에 관한 연구 (Acute Toxicity of Bovine Somatotrophine-Sustained Release(BST-SR) in Rats and Mice)

  • 강경선;이영순
    • 한국식품위생안전성학회지
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    • 제6권3호
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    • pp.185-189
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    • 1991
  • BST-SR의 마우스 (ICR)와 랫드(S.D)에서의 급성 피하 독성을 조사하기 위하여, 본 시험 물질을 암수 각각 소에서 임상용량인 500mg/600kg의 일정한 공비로 최고 1000배 까지의 용량으로 경배부위로 1회 피하투여하여 1주일간 관찰하였으나 일반적으로 임상증상에서 아무런 이상을 발견할수 없었으며, 체중변화나 전 생존 동물의 부검에서도 아무런 이상을 발견할 수 없었다. BST-SR의 시험물질은 소에서의 임상적용 용량 1000배 까지의 투여로도 아무런 독성이 관찰되지 않은 것으로 미루어 보아 현재의 임상적용용량은 상당히 안전할 것으로 사료된다.

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지속성 구강점막 부착형 Acyclovir 정제의 제조 및 평가 (Preparation and Evaluation of Sustained Release Oral Adhesive Type Acyclovir Tablet)

  • 박양환;정비환;차봉진;권종원;양중익;민신홍
    • 약학회지
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    • 제34권3호
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    • pp.155-160
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    • 1990
  • An oral adhesive tablet of acyclorir [9-(2-hydroxyethoxymethyl) guanine] for herpetic stomatitis was prepared and its physical properties were evaluated. 300 mg weighed tablets containing 30 mg of acyclovir were prepared with six kinds of polymers from direct compression, and the stickiness, fracture resistance and dissolution in pH 6.8 buffer solution were tested. HPMC and MC showed good stickiness and fracture resistance, and their dissolution rates were significantly different from each other. Three factors-HPMC:MC ratio, acyclovir content, compression force-were chosen as an important factor of manufacture and factorial analyses for these three factors were carried out. Eight kinds of formulations from different combination of three factors were prepared and tested in stickiness, fracture resistance and dissolution in pH 6.8 buffer solution. Dissolution rate was significantly affected by polymer ratio, fracture resistance was affected by compression force, and stickiness was not significantly affected by acyclovir content and polymer ratio.

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Protein Drug Oral Delivery: The Recent Progress

  • Lee, Hye-J.
    • Archives of Pharmacal Research
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    • 제25권5호
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    • pp.572-584
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    • 2002
  • Rapid development in molecular biology and recent advancement in recombinant technology increase identification and commercialization of potential protein drugs. Traditional forms of administrations for the peptide and protein drugs often rely on their parenteral injection, since the bioavailability of these therapeutic agents is poor when administered nonparenterally. Tremendous efforts by numerous investigators in the world have been put to improve protein formulations and as a result, a few successful formulations have been developed including sustained-release human growth hormone. For a promising protein delivery technology, efficacy and safety are the first requirement to meet. However, these systems still require periodic injection and increase the incidence of patient compliance. The development of an oral dosage form that improves the absorption of peptide and especially protein drugs is the most desirable formulation but one of the greatest challenges in the pharmaceutical field. The major barriers to developing oral formulations for peptides and proteins are metabolic enzymes and impermeable mucosal tissues in the intestine. Furthermore, chemical and conformational instability of protein drugs is not a small issue in protein pharmaceuticals. Conventional pharmaceutical approaches to address these barriers, which have been successful with traditional organic drug molecules, have not been effective for peptide and protein formulations. It is likely that effective oral formulations for peptides and proteins will remain highly compound specific. A number of innovative oral drug delivery approaches have been recently developed, including the drug entrapment within small vesicles or their passage through the intestinal paracellular pathway. This review provides a summary of the novel approaches currently in progress in the protein oral delivery followed by factors affecting protein oral absorption.

Modeling of Reinforced Concrete for Reactor Cavity Analysis under Energetic Steam Explosion Condition

  • Kim, Seung Hyun;Chang, Yoon-Suk;Cho, Yong-Jin;Jhung, Myung Jo
    • Nuclear Engineering and Technology
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    • 제48권1호
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    • pp.218-227
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    • 2016
  • Background: Steam explosions may occur in nuclear power plants by molten fuel-coolant interactions when the external reactor vessel cooling strategy fails. Since this phenomenon can threaten structural barriers as well as major components, extensive integrity assessment research is necessary to ensure their safety. Method: In this study, the influence of yield criteria was investigated to predict the failure of a reactor cavity under a typical postulated condition through detailed parametric finite element analyses. Further analyses using a geometrically simplified equivalent model with homogeneous concrete properties were also performed to examine its effectiveness as an alternative to the detailed reinforcement concrete model. Results: By comparing finite element analysis results such as cracking, crushing, stresses, and displacements, the Willam-Warnke model was derived for practical use, and failure criteria applicable to the reactor cavity under the severe accident condition were discussed. Conclusion: It was proved that the reactor cavity sustained its intended function as a barrier to avoid release of radioactive materials, irrespective of the different yield criteria that were adopted. In addition, from a conservative viewpoint, it seems possible to employ the simplified equivalent model to determine the damage extent and weakest points during the preliminary evaluation stage.

A New Formulation System for Slow Releasing of Phosphorous Acid in Soil for Controlling Phytophthora Diseases

  • Park, Hae-Jun;Kim, Sung-Ho;Jee, Hyeong-Jin
    • The Plant Pathology Journal
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    • 제23권1호
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    • pp.26-30
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    • 2007
  • Phosphorous acid is known to effectively control various Oomycetes diseases. The phosphoric acid moves upward and downward through the xylem and phloem in plants. The sustainable forms of the slow releasing chemical in rhizosphere would be ideal to be up-taken by plants. Therefore, we developed a new system for phosphorous acid formulation using a carrier coated with polysaccharides. When the product was applied in rhizosphere, the adequate amount of phosphorous acid was consistently released up to 4 weeks in rhizosphere soils. While soil drenching with phosphorous acid at 1,000 ${\mu}g/ml$ and metalaxyl at 150 ${\mu}g/ml$ were not effective to control pepper Phytophthora blight for 4 weeks, direct application of our formulation product around basal stem of pepper plants resulted in excellent disease control effect against Phytophthora blight over 4 weeks. The application of 4 g of our product per plant was optimum to control the disease, and 8 g product/plant did not cause phytotoxicity. Based on the results, we conclude that the applications of the formulation product once or twice during cropping season can control Phytophthora diseases on various crops.

Reliability studies on RC beams exposed to fire based on IS456:2000 design methods

  • Balaji, Aneesha;Aathira, M.S.;Pillai, T.M. Madhavan;Nagarajan, Praveen
    • Structural Engineering and Mechanics
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    • 제59권5호
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    • pp.853-866
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    • 2016
  • This paper examines a methodology for computing the probability of structural failure of reinforced concrete beams subjected to fire. The significant load variables considered are dead load, sustained live load and fire temperature. Resistance is expressed in terms of moment capacity with random variables taken as yield strength of steel, concrete class (or grade of concrete), beam width and depth. The flexural capacity is determined based on the design equations recommended in Indian standard IS456:2000. Simplified method named $500^{\circ}C$ isotherm method detailed in Eurocode 2 is incorporated for fire design. A transient thermal analysis is conducted using finite element software ANSYS$^{(R)}$ Release15. Reliability is evaluated from the initial state to 4h of fire exposure based on the first order reliability method (FORM). A procedure is coded in MATLAB for finding the reliability index. This procedure is validated with available literature. The effect of various parameters like effective cover, yield strength of steel, grade of concrete, distribution of reinforcement bars and aggregate type on reliability indices are studied. Parameters like effective cover of concrete, yield strength of steel has a significant effect on reliability of beams. Different failure modes like limit state of flexure and limit state of shear are checked.